Apparatus for superheating steam



Filed. June 22, 1925 H HARTMANN APPARATUS FOR SUPERHEATING STEAM Feb. 28, W2@

Patented Feb. Z8, i928.

Unire "rsi" OTTO rr, HARTMANN, F ossEL-WiLinnLMsHonE, ennirAnY;ass1GNon To sonivfrin'r'scirn HEissnai/rPn-ensnnnsonarfr ivi. i3. ir., @sassari-WILHELM- siioiin, GERMANY, A CORPORATION OF GERMANY. i Y

APPARATUS non vsuenaHEATING STEAM. v

pplication ledrJune 22, H25,

Mv invention relates to the super-heating of steam in connection with high-pressure A and high-temperature steam power plants.

`The invention consists mainly in the provi# sion of an apparatus designed to carry out a inethod'ot superheating steam according to Twhich ,extia-high-pressure vlive ysteamv superheated to a high temperature'inl a flue superheater, is utilized in an'intermediate superheater to superheat toa high teinper-' ature (at least 300 C.) the high-pressure exhaust steam from the extra-high-pressure stage of the engine to the high-pressure stage and thereupon is re-superheated to the temin the speciiication and claims does not only signify the extra-highpressure stage of an engine designed-from the outset fon suoli high pressures which, come into consideration, but 'it also signifies an additional extrahigh-pressure stage added to an existing engine designed for VOrdinary steam pressures `which additional (stageA might also be termed super-stage.) f Y l Withthis method for the carryingout oi which the apparatus of the present invention is designed, the pressure drop between the steam generator and engine is utilized for overcoming the resistance of the super-V heater tubes.

Tie steam usedin thel intermediate superheater as heat-,carrier can beforea'dmission to the second flue superheaterbemixed with live steam yin a nozzle or otherstea-m admixing device.

`i`rrrangements embodying the present invention are shown diagrammatieally byv Way oit-example in the accompanying drawings,

vin which Fig. lV shovvs in elevation avboiler plant embodying oneformof my invention and Fig. 2 isE a similar View embodying a modified form of my invention.

In the illustrative form shown in Figure kl, live steam is taken from the steam-andwater drum, 2, of the boiler, 1, through the pipe, 3, and is superheated to a high teinperature in the flue superheater, 4. This highly superheated extra-high-pressure steam passes thronghthe pipe, 6, into the coil sys- After Serial No.l 38,717, and in Germany uly 5, 1524.

tem of a lheat exchanger, Z, into'wlii'ch through a pipe, 8, exhaust steam, of' highl pressure is admittedrirom theV extra-high-v pressure stage, 9, ofthe engine and is there superheated tota temperature of at least l3G00 C, The exhaust `stea'mvthus highly j superheated passes throughjthe pipe, 10,*to a second stage, 11, oi" the engine hereinafter referred toas the lhigh#pressure stage. rillhe steam used as heat `carrier in the heat ex;v changer passes through the pipemlQ in theY direction shown by the arroivs into'ay second line superheater, le, and is there,re-,super-r heated to the desired high temperature `in order to ,pass through the pipe, 15, tothe extra-high-pressure stage of the engine.

A by-pass, 16., Vprovided Vwithy a shut-oit valve is indicated inndotted,lines,"the ob ject oil this arrangement being to render oi the exhaust steam between the engine stages and also the superheatingof the live steam itself.

ln the*arrangementshown in lFigure possible the regulation of theesuperheating'y ste'ainserving as the heatcarrierior .the

heat exchanger is takenhthrougli 'the pipe," lnfronithe boilerro'f the power `plant and highly super-heated in the superheater 18. passing through the heat exchanger, 7,

this steam is mixed vwith boiler steam sup-A plied suitable `a'dniixing .device `19v com,- z munieat-ing W1th? the boiler vdrum through the pipe, ftheftotal quantit'y of steam thus 'provided for v the extra-hi gli-pressure engine stage4 iliassingv tothe, iiue` superheater, 45d,

Where it is superlieated f g the ydesired degree.V based kon the following ,p

Theiiivention is considerations A .K t u t investigations have shown that heat transfer is especially favourable if highlyfsuper heated steam of at least 50. atmospheres pres; surel is utilizedfasthe heat carrierand ifrthe steam to be superheated isiilrewise ata high" pressure, for example lOwOr more.,atnfios;l pheres. Such a case arises, for example, in the superheating of an additional extra-high-pres'sure engine stage added to an existing engine of ordinaryhigh-pressure, when a steam temperature ot' 350 toriOOF C. is usually required `for the high-pressure stage While the exhaust steam from the additional extra-high-pressure stage of the engine has a temperature the exhaust steam from `a known manner by highly-superheateo steam, the steam utilized as heat carrier aty `the outlet from the heat exchanger, even it of only 200 to 2e-OO C. In such circumstances 5() to 100 and more heat units are there'lore to be added to each lrilogian'i of steam in the heat exchanger. It this heat were added lin live originally superheated to the extreme practical upper limit of about 450 C., would have too low a temperature tor-the eilicient y working ot the extra-high--pressure stage or vthe additionalstage of the engine. rOn the other-hand, withthe method to which the kpresent invention is appliedythe highly-l superheated extra-higli-pressure steam used as heat carrier, on adn'iission both to the extra-high-pressure and also to the lower pressure stages of the engine has the desired high temperature to enable the cycle to be carried out with a high thermal ,eiiiciency Asthe extra high-pressure live .steam has Y a very small speciiie volume, thecross-see-` tions of the pipes between the boiler and the heat exchanger' and between the latter and yzu the second superheater are comparatively small so thatV heat losses through radiation are very'slight. In addition the present invention presents the advantage that the heat- A ing surface of the heatV exchanger is very small and the latter can therefore be ar-I ranged in any desired position, Yfor example,

above or below the engine or alternatively it i canbe arranged at a greater or less dist-ance from the engine installation.

As the mean temperature difference. between the steam serving as heat carrier and the steam to be superheated is comparatively large, theheating surface. ot the heat ein changer in certain circumstances will be less than in the ease Where saturated steam` of 100 atmospheres and more pressureis ap rplied to the heating of the heat exchanger.

1 .A further. advantage of the present inven-` tion results from the fact that onlysuperheaters at the highest' working pressureare arranged in the flue gases, an arrangement i which my many years experience Vof high! f temperature steam has proved toibe the best.

' In methods hitherto' employed 'in v which the dering its installation diiticult because of the restricted space available for receiving it. Finally, a flue superheater.untilizing lowpressure steam is not so durable as one utilizing high-pressure steam, as the former at high temperatures readily becomesi'ed hot.

II/Vhat I claim is:

1.In asteam p-ower plant, the Ycombination with a boiler, of an engine having` sev eral expansion lstages including an extrahigh pressure stage and va `high pressure stage, a iirst sup'eiheater in said boiler to heat the steam therefrom. to highly-supery heated condition, a heat exchanger .ii'iter-k n posed between the exhaust of said extra-high pressure engine stage and thek hi gh pressure stage, and in which the highly superheatedextra-high pressure steam from said ti t superheater is utilized as a heat carrier to re-hcat the high pressure exhaust steam trom said extra-high pressure engine stageft'o a temperature of at least 300 C., a second superheater in said boiler, a lconduit c-onnecting said heat exchanger to said second superheater for passing'the steam so utilized as a heat carrier to said. second superheatcr.V and a second conduit connecting said second superheater to the extra-high pressure stageV of -the engine. Y y

2. In a steam vpower plant, the combination with a boiler, oi' anvengine haring several expansion stages including aniextrahigh-pressure stage and a high-pressure stage, a iirst superheater in said boiler toy heat the steam therefrom to highly-super-V heated condition, a heat exchanger interposed between the exhaust of said extra-highpressure `engine stage and the high-pressureV stage, and in which the highlysuperheated extra-high-pressure,steam 'from said first supcrlicater is utilized as `a'he'a't carrier to re'- heat the,high-pressure exhaust steam from' said extra-high-pressure engine stage to ateinperature'ot lat least 300 C., a second superheater in said boil-er, a conduit connecting said heat exchanger to said second supervheater for passing the steam so utilized as a heat carrier to saidfsecond superheater, ay steam admixing device inserted in said cron,-

duit and connectedl with the steam space of said boiler, and a second conduit connecting said second superheater to the extra-highpressure stage of the engine. y y

1n testimony whereof I have hereunto set my hand. i Y

vvorro H. HARTMANN 

